Small Injuries Can Cause Lasting Vocal Ills, Doctors Say

By JANE E. BRODY

Published: September 13, 1988

A RECENT study suggests that minor fractures of the cartilage in the larynx, which are often undetected and usually untended, may cause permanent damage to the voice.

The larynx is the voice box that houses the vocal chords. Fractures can result from a hard blow to the neck, such as might be sustained in an auto accident, a strangulation attempt or a chokehold.

In studies using cadavers, Dr. Robert B. Stanley Jr. of the University of Southern California in Los Angeles showed that small breaks in the laryngeal cartilage can interfere with airflow through the voice box or disturb the vibrations of the vocal cords. The analyses indicated that the fractures could result in lasting hoarseness or a limitation of pitch, the ability to produce high or low tones. Often Overlooked

Until recently, laryngeal fractures were generally overlooked because they do not show up in routine X-rays and, even when untreated, they rarely impair breathing.

Moreover, when doctors treat patients with vocal problems, less serious factors often account for distortions, among them are overuse, excessive smoking, a cold, a tracheotomy or other irritation. In most cases the distortion is temporary, disappearing with the underlying condition. But when the distortion does not disappear, a careful medical examination is in order.

Dr. Stanley said the fractures can now be readily detected by a CT scan, a computerized, three-dimensional X-ray. He added that many of the fractures should be treated to prevent permanent hoarseness or limited pitch.

''It seems as if even minor fractures can adversely affect voice quality,'' Dr. Stanley said in an interview. ''We can now diagnose these fractures, but we still are not sure what to do with them.''

He said the fractures can be corrected with a ''fairly minor operation'' in which laryngeal cartilages are realigned and held in place with fine wires permanently installed through a small incision in the neck.

What is not yet known, however, is which kinds of fractures require correction and which can be left alone without concern for voice quality.

In his studies, five cadaver larynxes were mounted on a special laboratory apparatus that permitted air to flow through them, similating the airflow when a person produces sounds. Various fractures were inflicted on the larynges simulating typical minor injuries and the resulting changes in airflow and vocal cord function were assessed.